scholarly journals Analysis of factors influencing Cu(II) sorption by clinoptiolite

2013 ◽  
Vol 67 (5) ◽  
pp. 739-745
Author(s):  
Marija Sljivic-Ivanovic ◽  
Ivana Smiciklas ◽  
Jelena Markovic ◽  
Aleksandra Milenkovic

Experimental design methodology represents a powerful tool for the analysis and optimization of various processes. Immobilization of toxic substances by sorption onto low-cost materials gained a lot of attention in the last decade. Fundamental knowledge about sorption processes and their practical use can be improved by experimental planning and statistical analysis. In this study, the effects of initial metal concentration and pH, as well as the sorbent mass and particle size, on Cu(II) sorption by natural clinoptilolite were evaluated and compared. Full factorial experimental design at two levels was applied. Statistically significant factors were determined considering residual Cu(II) concentrations as a system response. The Pareto graphs of standardized effects, Main effect plots and Interaction plots were created using statistical software. Initial sorbate concentration, sorbent mass and their interaction were recognized as statistically significant, at 95 % confidence level. Main effect plot approved that sorbent mass increase and initial Cu(II) concentration decrease caused reduction of residual Cu(II) concentration in solution. On the other hand, the change of initial solution pH and sorbent particle size didn?t provoke significant response changes. Bearing in mind that pH is the factor with large effect on heavy metal sorption, insignificant influence of initial pH detected in this study can be explained by buffering properties of the applied clinoptilolite and relatively narrow pH range chosen in order to prevent sorbent dissolution on one side and sorbate precipitation on the other. By regression analysis, the mathematical model for process description was derived. The correlation between predicted and experimental values was high (R2>0.99). In the investigated ranges of parameters, the obtained empirical equation can be applied for the prediction of system response.

Author(s):  
Redouane Ouafi ◽  
Anass Omor ◽  
Younes Gaga ◽  
Mohamed Akhazzane ◽  
Mustapha Taleb ◽  
...  

This research investigates the adsorption potential of pine cones powder (PCP) for the removal of copper ions (Cu(II)) from aqueous solutions. The process of adsorption was reasonably fast to be completed within a time of 60 min. The pseudo-second order kinetic model describes properly the Cu(II) adsorption by PCP. The adsorbent was characterised by various instrumental techniques and batch experiments were conducted to investigate the effect of PCP dose, solution pH, particle size and initial Cu(II) concentration on adsorption efficiency. Optimum Cu(II) removal occurred at a slightly acidic pH, with a particle size less than 100 ?m. The effective PCP dose was estimated to be 36 g.L-1. The increase in the initial concentration of Cu (II) was accompanied by a reduction in the rate of its reduction by almost half. The Langmuir model was the best fitting isotherm with a maximum adsorption capacity of 9.08 mg.g-1. The thermodynamic parameters values showed that the Cu(II) adsorption was a spontaneous and endothermic process. The results of this research suggest that Cu(II) could be removed through an environmentally friendly process using PCP as low-cost natural wastes.


2021 ◽  
Vol 12 (1) ◽  
pp. 1247-1262

This research work involved using factorial experimental design techniques to investigate the adsorption of hexavalent chromium from an aqueous solution on medlar activated carbon. A 24 full factorial experimental design was employed to determine the optimum values and degree of importance of parameters: pH, initial Cr (VI) concentration, adsorbent dose, and contact time at two levels. The optimized conditions for hexavalent chromium Cr (VI) removal were at initial pH 1.5, 5 mg.L−1Cr (VI), adsorbent dose 6 mg, and 60 min adsorption time. The results predicted a good agreement between the predicted values (R2= 0.9909), as obtained by the model, and the experimental value (R2= 0.9977). The main effects and interaction effects were analyzed using analysis of variance (ANOVA), F-test and P-values to define the most important process variables affecting Cr (VI) adsorption. The most significant variables were therefore the pH of the solution and the adsorbent dose. Therefore, the present results demonstrate that medlar activated carbon should be regarded as a low-cost alternative for removing Cr (VI) from an aqueous solution. The adsorption data were evaluated by Langmuir, Freundlich, and Dubinin-Radushkevich isotherms. The results showed that the Langmuir isotherm model best describes the equilibrium adsorption with a high correlation coefficient.


2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
A. Thiam ◽  
K. Tanji ◽  
O. Assila ◽  
M. Zouheir ◽  
Redouane Haounati ◽  
...  

In this work, the adsorption of Remazol Brilliant Blue (RBB) over raw date pits (RDPs) as an inexpensive adsorbent has been examined. In addition, all parameters such as the adsorbent mass, solution pH, RDP particle size, RBB initial concentration, and temperature on the adsorption of RBB influencing the adsorption procedure were studied to provide fundamental information of the adsorption equilibrium. The characterization of RDP material is investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). Based on the calculation, the kinetic rate of the adsorption was well modeled by pseudo-second-order and Langmuir isotherm. Surface functional groups of RDP have substantially been influenced by the adsorption characteristics of RBB. The capacity of the adsorption has achieved 105 mg/g and a removal efficiency of 90.4% at 1.5 g/L RDP mass, 40 mg/L initial dye concentration, pH 2, temperature of 328 K, 40 µm particle size, and contact time of 50 min. The capacity of the adsorption could reach 198 mg/g by increasing the ionic strength of RBB solution. Desorption tests showed that RDP adsorbent has the disadvantage of losing efficiency while reusing for many cycles. However, it still abundant and inexpensive. Therefore, RDP can be used as a potential low-cost bioabsorbent for the elimination of RBB from wastewater.


1970 ◽  
Vol 33 (2) ◽  
pp. 167-178
Author(s):  
Tajmeri SA Islam ◽  
Hosne Ara Begum ◽  
Mohammad Abul Hossain ◽  
Mohammad Tanvir Rahman

Batch sorption study was performed using used black tea leaves (UBTL) as a low-cost adsorbent for the removal of lead (II) from aqueous solutions. Experiments were conducted as a function of contact time, initial metal ion concentration, solution pH and temperature. The sorption of Pb(II) on used tea leaves increases with increase of initial pH of solution upto a certain limit which corresponds to the pH nearly 5. The sorption isotherms follow Langmuir equation better than Freundlich equation. Again the Langmuir equation is more applicable at higher temperatures compared to those at low temperature at all pH. The monolayer sorption capacity decreases with increase in processing temperature but the overall sorbed amount increased with the increase in temperature at all pH. The positive value of estimated heat of sorption suggests the activated sorption. A probable mechanism of the sorption of Pb(II) on used tea leaves was proposed based on the surface charge of used tea leaves and the change of charge of Pb(II) with the pH of solution. DOI: 10.3329/jbas.v33i2.4100 Journal of Bangladesh Academy of Sciences, Vol. 33, No. 2, 167-178, 2009


2020 ◽  
Vol 2020 ◽  
pp. 1-11 ◽  
Author(s):  
Rekha Singh ◽  
Tony S. Singh ◽  
John O. Odiyo ◽  
James A. Smith ◽  
Joshua N. Edokpayi

This paper presents a study on batch sorption of methylene blue dye from aqueous solution onto Ginkgo biloba sorbent, a waste material produced during the Fall season in many parts of the world. Batch kinetics, equilibrium, and thermodynamic studies were conducted to evaluate the effect of contact time (0–150 min), sorbent dose (0.5–3.0 g/L), pH (2–11), temperature (30–50°C), initial MB concentration (10–30 mg/L), and particle size (177 μm—590 μm) on the methylene blue dye sorption. More than 99% removal of methylene blue was observed within 120 minutes. A Lagergren pseudo-first-order model, a pseudo-second-order model, and intraparticle diffusion models fitted well to the kinetics experimental data. Langmuir and Freundlich isotherm models also fitted well with the observed equilibrium data. Additionally, removal of methylene blue increased with increase in solution pH. Higher sorption capacity (∼20 mg/g) was observed with smaller particle size (170 μm) as compared to larger particle sizes (590 μm). Thermodynamic parameters such as ∆G°, ∆H°, and ∆S° indicated that the sorption process was feasible, spontaneous, and endothermic in nature. The study shows that Ginkgo biloba leaves have the potential to be an efficient sorbent for the removal of methylene blue from surface water samples.


2013 ◽  
Vol 10 (1) ◽  
pp. 108-113

Fly ash is an important industrial by-product that comes from the combustion of coal, for the production of electrical energy. In our country, only a small percentage is used for the construction of technical projects, while the rest is stockpiled, causing serious problems. Because of its great availability and its low cost, further possibility of its usage should be investigated. In the present assignment, clay soils, natural and crushed sand-gravel were stabilized with different quantities of fly ash, for the creation of durable forest roads. From research, it has been found that stabilization with fly ash, improves the natural and mechanical characteristics of soils (plasticity, compressive strength and particle size distribution). As a result, the improvement of the forest road networks from one side and the economy in natural inert materials and the exploitation of fly ash from the other, the importance of such an intervention in the protection of the forest ecosystem and the natural environment in general are obvious.


2014 ◽  
Vol 945-949 ◽  
pp. 1408-1411
Author(s):  
Lei Quan ◽  
Fang Wang ◽  
Rong Li

In this paper we introduce the concept of an agile electronic pest control intelligent device for commercial usage and we have evaluated its performance in comparison with other existing similar technologies. The frequency and intensities are changed with respect to the target pest however human behavior has been found to be inert with their exposure. The unit has been tested in lab conditions as well as field testing done have given encouraging results. The device can be a standalone unit and hence work for small scale viz. kitchen garden on the other hand multiple devices acting in coordination with each other give the desired output on a larger scale. Lastly, we chose a tricopter over the wider used quadcopter for greater yaw and agility. The work was funded by IEEE under AiyeHum – 2012 and the prototype was successfully built and tested. The system response effectiveness was found to 86.5% up to a distance of 15 meters.


2014 ◽  
Vol 804 ◽  
pp. 59-62
Author(s):  
Lian Ai ◽  
Xue Gang Luo ◽  
Xiao Yan Lin

Low cost agricultural by-products are potential materials for water pollution treatment such as removal of radionuclide. This paper deals with removal of strontium ions from aqueous solution using sunflower stem (SFS) and leaf (SFL). Batch sorption experiments were performed as a function of initial solution pH, adsorbent dosage and initial strontium (II) concentration. The removal efficiency of strontium (II) increased with initial pH and achieved maximum values at a pH range of 4.0-7.0 both for SFS and SFL. The isotherm adsorption data was modeled best by the nonlinear Langmuir-Freundlich equation. The maximum sorption capacity of SFS and SFL were observed to be 17.87 and 22.31 mg/g under optimal conditions, respectively.


2017 ◽  
Vol 76 (12) ◽  
pp. 3307-3318 ◽  
Author(s):  
Tingting Qin ◽  
Zhaowei Wang ◽  
Xiaoyun Xie ◽  
Chaoran Xie ◽  
Junmin Zhu ◽  
...  

Abstract The biochar was prepared by pyrolyzing the roots of cauliflowers, at a temperature of 500 °C under oxygen-limited conditions. The structure and characteristics of the biochar were examined using scanning electron microscopy, an energy dispersive spectrometer, a zeta potential analyzer, and Fourier transform infrared spectroscopy. The effects of the temperature, the initial pH, antibiotic concentration, and contact time on the adsorption of norfloxacin (NOR) and chlortetracycline (CTC) onto the biochar were investigated. The adsorption kinetics of NOR and CTC onto the biochar followed the pseudo-second-order kinetic and intra-particle diffusion models. The adsorption isotherm experimental data were well fitted to the Langmuir and Freundlich isotherm models. The maximum adsorption capacities of NOR and CTC were 31.15 and 81.30 mg/g, respectively. There was little difference between the effects of initial solution pH (4.0–10.0) on the adsorption of NOR or CTC onto the biochar because of the buffering effect. The biochar could remove NOR and CTC efficiently in aqueous solutions because of its large specific surface area, abundant surface functional groups, and particular porous structure. Therefore, it could be used as an excellent adsorbent material because of its low cost and high efficiency and the extensive availability of the raw materials.


2013 ◽  
Vol 14 (3) ◽  
Author(s):  
Eriawan Rismana ◽  
Susi Kusumaningrum ◽  
Olivia Bunga P ◽  
Idah Rosidah ◽  
Marhamah Marhamah

The chitosan – Garcinia Mangostana extract nanoparticles has been prepared by ionic gelation reaction by mixture 0.2 % chitosan solution in acetic acid with Garcinia Mangostana extract and it’s continued by reaction process with 0.1 % sodium tripolyphosphate. The particle size of material was determined by Particle Size Analyzer (PSA) that it showed in the range of 200 – 500 nm. The color, pH, water, α- mangostin, mercury, arsenic, cadmium, lead, totally microbe aerobic, totally mold and yeast, and solvent residue contents of nanoparticles were also examined by many methods that these resulted are yellow, 4.50 – 5.50, 89 – 90 %, 1.05 %, < 0.005 ppm, < 0.01 ppm, < 0.01 ppm, < 0.05 ppm, < 10 CFU/g, < 10 CFU/g and not detected, respectively. The other characterization was also observed that it’sincluded stability andTLC chromatogram. A mixture of nanoparticles with cosmetics bases was showed that it’s increased stability, homogeneity and easy to formed.


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